肺与外界空气进行气体交换叫做肺通气，它的作用是使气体进出肺泡，以便实现肺换气，即肺泡与毛细血管血液间的气体交换。肺通气量是指单位时间内进出全部呼吸道的气体总量。但是每次呼吸进出呼吸道的气体并不能都进出肺泡，即肺泡通气量少于肺通气量，这是为什么呢？已知从鼻 The exchange of air between the lungs and the outside air is called lung ventilation, its role is to make the gas out of the alveoli, in order to achieve lung ventilation, that is, the exchange of gas between the alveoli and capillary blood. Pulmonary ventilation refers to the total amount of gas that enters and exits the entire respiratory tract within a unit of time. But each time you breathe in and out of the respiratory gas can not have access to alveoli, alveolar ventilation is less than lung ventilation, which is why? Known from the nose